Deep-sea anglerfish
Melanocetus johnsonii
- Size
- Females about 15 to 18cm long
- Look for it
- All year round
- Where
- The deep, dark waters of every ocean
A round, black fish with a huge mouth of needle teeth and a glowing lure on a rod above its head.
The anglerfish that follows you
This page is the deep sea, a mile and more below the waves, where no sunlight reaches. Move your pointer and your animal will swim after your light. Choose a different animal at the bottom, and tap the notes to open them.
01 · LureA fishing rod
A spine on its head ends in a bulb of glowing bacteria, which it waggles to draw prey close.
02 · MouthA huge mouth
Its mouth and stomach stretch so far that it can swallow a fish twice its own size.
03 · MaleA tiny male
The male is only a few centimetres long. His one job is to find a female in the dark.
04 · TeethTeeth that fold
Its long teeth fold inwards to let prey in, then spring back so that it cannot get out.
05 · BlackBlacker than black
Its skin soaks up almost all light, so even its own glow does not give it away.
06 · NameThe black seadevil
This kind is also called the humpback anglerfish, or the black seadevil.
Meet them all
Who's who in the deep
Giant squid
Architeuthis dux
- Size
- Up to 12 or 13m long, including the tentacles
- Look for it
- All year round
- Where
- Deep water in every ocean
A huge, red squid with eight arms, two very long feeding tentacles and enormous eyes.
Sperm whale
Physeter macrocephalus
- Size
- Up to 18m long
- Look for it
- All year round
- Where
- Deep water in every ocean
A huge, dark-grey whale with a great square head a third of its length, and wrinkled skin.
Lanternfish
Myctophidae
- Size
- Mostly 5 to 15cm long
- Look for it
- All year round
- Where
- Every ocean, deep by day and near the surface at night
Small, silvery, big-eyed fish with rows of tiny lights along their sides and bellies.
Dumbo octopus
Grimpoteuthis
- Size
- Mostly 20 to 30cm long
- Look for it
- All year round
- Where
- The deep sea floor in every ocean, down to 7,000 metres
A small, soft, pinkish octopus with a pair of ear-like fins on its head and a skirt of skin between its arms.
Gulper eel
Eurypharynx pelecanoides
- Size
- Up to 75cm long
- Look for it
- All year round
- Where
- Deep water in every ocean
A black eel that is mostly mouth: a huge, loose, pouch-like jaw on a long whip of a body, with a light at the tip of its tail.
Through the year
When to look for them
There are no seasons in the deep sea: it is dark and cold all year, so every one of these is always about. The animal following you is shown in red.
Anglerfish
Giant squid
Sperm whale
Lanternfish
Dumbo octopus
Gulper eel
Good to know
Six things about the deep sea
No sunlight
Below about 1,000 metres there is no sunlight at all. It is completely dark, all the time.
Living lights
Most deep-sea animals make their own light, to find food, find a mate or confuse a hunter.
Crushing pressure
The weight of water above is enormous: like having several cars stacked on your thumbnail.
Nearly freezing
The deep sea is only a few degrees above freezing, everywhere in the world.
Marine snow
Food drifts down from above as a slow fall of flakes: bits of dead plants and animals.
Why so many are red
Red light does not reach the deep, so a red animal looks black and is invisible.
Photo gallery
Real photos of the animals on this page. Tap one to see it bigger.
Deep-sea anglerfish
Giant squid
Sperm whale
Lanternfish
Dumbo octopus
Gulper eel
Photos are from Wikimedia Commons and are used under free licences. They have been resized, and cropped where they appear in link previews. Open a photo to see who took it.
The last great unknown
The deep sea is the biggest living space on Earth, and the least explored. We have better maps of the Moon. Almost every expedition finds animals nobody has seen before.
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